Of these, the Compton-like process is typically smaller, suffering an additional \(T_d^2/M_\chi ^2\)  suppression.
At high temperatures, \(T_d \gtrsim m_\phi \) , the momentum transfer rate between the DM and the WZDR sector from the t-channel process scales as [1]}
\(\Gamma \propto \frac{T_d^2 }{M_\chi } \qquad \text{for }T_d \gtrsim m_\phi ~,\) 
